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 Product List

Auto Bearings


Front Wheel Hub Bearings
  Rear Wheel Hub Bearings
 

Tensioner&Idler Bearings

 

Clutch Release Bearings

 

Wheel Hub Bearing(One Generation)

 

Wheel Hub Bearing( second generation)

 

Wheel Hub Bearing ABS System

 

Water Pump Bearing

 

Automotive Tapered Roller Bearings

 

Steering Wheel Bearings

 

Universal Joint Kits

    Automobile Center Support Bearing
  Steering Gear Box Bearings
  Special Non Standard Auto Bearing
  Automobile Alternator Bearing
  Automotive Air Condition Bearings

Industry Bearing


Deep Groove Ball Bearings
  Angular Contact Ball Bearing
 

Cylindrical Roller Bearings

 

Self-Aligning Ball Bearing

 

Spherical Roller Bearings

 

Tapered Roller Bearings

 

Bearing Units

 

Thrust Bearings

 

Needle Roller Bearings

 

Linear Bearings

 

Special Non Standard bearings

Power Transmission Parts


Ball leading Screw

 

Linear Motion Shaft

  Linear Guide Rail and Block Assemblies
  Precise Crossing Guide Rail

Auto Steering Gears


Worm and level Steering Gears

 

Rack and Pinion Type Steering Gears

 

Recirculating Ball Type Steering Gears


  Bearing Technology

Bearing Material Retainer (cage) Closures Load Rating Radial Play
Maximum Speed Shaft/housing fit Tolerance Frictional Torque Noise Rating Lubricants

8. Tolerance

Tolerances control the dimensional accuracy of the bearing. We use ISO tolerances and these are given in microns or thousandths of a millmetre. AFBMA tolerances in ten-thousandths of an inch are also often used with bearings. The equivalents are as follows: P0 = Abec1; P6 = Abec3; P5 = Abec5; P4 = Abec7. Tolerances have no effect on radial play although it is sometimes mistakenly thought that improving the tolerances will produce a bearing with less play. Assuming that the shaft and housing are manufactured to the same tolerances as the bearing, higher bearing tolerances will produce better mating between shaft/housing and bearing, lower noise and vibration due to improved roundness and lower starting and running torque (also subject to radial play and lubricant). For exact tolerance limits, please view our TOLERANCE TABLES. For an explanation of how tolerances are measured, see TOLERANCE TIPS.

9. Frictional Torque

This affects the free-running of the bearing. Spin a bearing containing stiff grease with your finger and not much happens - relatively high frictional torque. Try a bearing with no lubrication and it will spin freely - low frictional torque. The effort required to rotate a bearing depends greatly on the roundness of the bearing, the load applied, the lubrication and the closures. Better roundness and surface finish of the balls and raceways means less effort is needed to rotate the bearing. The greater the load, the greater the deformation of the bearing components leading to increased resistance. As for lubrication, instrument oils will often produce lower torque levels especially at very low speeds but the difference between these and many low torque greases is actually very small, particularly if a low grease fill is used. A standard low torque grease such as Multemp SRL grease may give an increase of only 20 percent over a Aeroshell 12 oil. This can drop to under 5 percent for very low torque greases if a low (e.g 10 to 20 percent) fill is used. High viscosity lubricants can significantly increase bearing torque due to greater lubricant drag. Torque levels for a greased bearing are briefly higher to start with as the grease takes a short time to "run in" or be distributed inside the bearing. Contact seals will greatly increase the torque figures.The effort required to rotate a bearing from rest (starting torque) is slightly greater than the effort required to keep it rotating (running torque).
Approximate figures for frictional torque for can be calculated using a simple formula. This is only valid if the bearing has low torque lubrication (and the grease fill is not high), is open, shielded or has non-contact seals and is subjected to low speed and low load. For radial ball bearings, the axial load should be less than 20 percent of the radial load while the load should be purely axial for thrust bearings. Contact us if you need more accurate figures taking into account the speed and the lubricant viscosity. The measurements are in Newton millimetres (Nmm). This is a compound unit of torque corresponding to the torque from a force of one newton (approx 0.1 Kgf) applied over a distance arm of one millimetre.

Frictional torque (measured in Nmm or Newton millimetres)
Radial ball bearings:   0.5 x 0.0015 x radial load in Newtons* x bearing bore (mm)
Axial ball bearings:    0.5 x 0.0013 x axial load in Newtons* x bearing bore (mm)
*10 Newtons = 1 Kgf


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